Thermostatically operated switch



June 15, 1937. J, PAGANO 2,084,214

THERMOSTATICALLY OPERATED SWITCH Filed Feb. 18,' 1935 FIG. 1.

Ulf INVENTOR.

Juaelnh Pagano BY I ATTORNEY Patented June 15, 1937 PATENT .OFFICE 2,084,214 THERMos'rA'rIoALLY OPERATED SWITCH Joseph Pagano Memphis, Tenn.

Application February 18, 1935, Serial No. .7,087

4 Claims.

The present invention relates broadly to automaticall'y controlled igniting devices for gaseous fuel burners and more particularly to an improved therrnostatically operated switch device for automatically controlling electrical igniting circuits for gaseous fuel burners.

The primary object of the present invention is to provide a thermostatically operated circuit controlling device for electrical igniting circuits for gaseous fuel burners, wherein the control period is independent of the degree of temperature at which the operation takes place.

.a further object is to provide a thermostatically operated circuit breaker device wherein the degree of movement, of the switch arm is independent oi the degree of movement of the thermostatic actuating means therefor. 5

A further object is to provide a thermostatically operated switch of this character which is oi extremely simple and durable construction and which will operate to quickly close an igniting circuit irrespective of the temperature of the thermostatic actuating means therefor.

Other objects and advantages of the inventionwill be apparent from the following detailed description, `taken in connection with the accompanying drawing, forming a part of this specication and in which drawingz- Figure l is a View in front elevation of an open 30 type gas heater provided with the improved electricaligniting means.

Figure 2' is an enlarged plan view of the circuit breaker showing the switch arm in its circuit cloing position and its connection to the thermosta Figure 3 is a section on the line 3 3 of Figure 2.

Figure l is a plan view of the circuit breaker showing the position of the switch arm ywhen temperatures at the thermostat have dropped below normal.

Figure 5 is a plan View of the circuit breaker showing the position of the switch arm when moved to an open circuit vposition by the heated thermostat.

In the drawing, and wherein like reference characters designate corresponding parts throughout the several views, the letter A may' designate a gaseous fuel burner provided with the electrical igniting means B embodying a thermostatically operated circuit breaker C.

The gaseous fuel burner A in the example shown is in the form of a gas heater and embodies a casing 5 having arranged therein a metal manifold or burner 6 to which is connected a gas sup- 55 ply pipe 1 provided with a control valve 8 having an operative handle 9 for controlling flow of gas to the burner B. The burner 6 is provided with a plurality of jets or nozzles I0 thru which the gas escapes and is ignited by the igniting means B.

Referring now to the electrical igniting means B for igniting the gas by means of an electrical spark, this means comprises a sparking electrode Il in the iorm oi a rod insulatively mounted at one end as at l2 upon the burner 6 and having its upperor opposite end formed into a point and terminating in slightly spaced apart relation to one of the jets lll to form a spark gap disposed in the path of the gas escaping from the jets.

Suitably mounted upon one end of the casing 5 is a vibrating coil or other suitable form of spark or high tension coil M with which is associated a transformer l5 having its primary terminals connected-to a power circuit i6. Connected between one low tension terminal il .of the transformer i5 and the terminal it of the vibrating coil I4 is a circuit wire i9, while connected between the high tension terminal 2li of the vibrating coil and the electrode li is a circuit wire 2l. Connected at one end to the terminal 22 of the coil l'l is a ground wire 23 having its opposite end grounded upon the-burner t as at "M, Connected between the low tension terminal 25 of the transformer iti and the terminal 22 of the vibrating coil i4 is an igniting circuit control line 26 in which is provided the thermostatically operated circuit breaker C and the manually operated switch means 2l.

This manually operated switch means 2l embodies a pair of contact members 23 and 29 insulatively mounted upon the valve t and arranged to normally contact one another when the valve is in an open position. Movable with the valve handle 9 is a lug 3 0 formed of a suitable insulating' material and so arranged as to engage the contact member 2d and move the same out of electrical contact with the contact member 29 when the valve is in a' closed position as shown in Figure l. Thus, when the valve d is closed, electrical circuit in the line 26 is broken and when the valve is opened, electrical circuit in the line 26 is completed thru the switch means 21.

Referring particularly to the construction and operation or the thermostatically operated circuit breaker C, the same operates for automatically controlling the igniting circuit in accordance with changing temperature conditions at the burner 6. The circuit breaker C comprises a suitable casing or housing 3| secured in a fixed position upon one end of the heater casing 5 at an elevation slightly above the upper side of the burner 6.

ing material and has mounted therein adjacent the outer end of the casing, a-stationary contact 32. Secured at one end within the casing 3| as upon a bracketl 33, is a spring contact arm 34 having a U-shaped free end portion 35 normally held against the lilxed contact 32 by the tension of the spring arm 34. Arranged within the casing 3| in cooperative relation to the free end portion 35 of the contact arm 34, is an adjustable stop 36 for limiting circuit breaking movement of the end portion 35 away from the contact 32. This adjustable stop 36 is set so that movement of the free end of the switch arm is just sufficient to break contact with the stationary contactr 32.

The igniting circuit control `line 26 includes a circuit wire 31 connected between the transformer terminal 25 and the stationary contact 32; a circuit wire 38 extending from the spring contact arm 34 to the contact member 29 of the switch means 21, and a circuit wire 39 extending from the contact member 28 to the terminal 22 of the vibrating coil I4. 'I'he opposite side of the control line 26 may include the circuit wire I9 connected with the coil l5 and thru the coil to the terminal 22 to which the circuit wire 39 is connected. The circuit breaker C and the switch means 21 are connected in the primary circuit.

Arranged to extend above the line of jets I0 is a thermostat 40 preferably in the form of a brass tube being threaded at one end and adjustably secured in a bracket 4| on the burner 6 by means of lock nuts 42 permitting adjustment of the thermostatic tube toward and from the circuit breaker C. The thermostatic tube 40 is so arranged as to be heated when the gas is lighted and when the gas is unlighted, the gas discharged from the jets acts to cool the tube. The opposite or free end of the thermostatic tube 40 extends slightly into the circuit breaker casing 3| for connectionto a control arm 43 serving to actuate the spring contact arm 34.

This control arm 43 embodies a bell crank or L-shaped lever pivoted at its elbow as at 44 and providing a short arm 45 extending transversely oi' the thermostatic tube 40 and a long arm 46 extending substantially parallel to the thermostatic tube. The free end of the tube 40 is pivotally connected as at 41 to the free end of the arm 45 whereby movement of the free end of the thermostatic tube swings the free end of the long arm 46 in a direction transversely of the casing The long arm 46 is preferably of channelshape and provides at its outer or free edge of a pair of spaced apart jaws or clampingl plates 48 for receiving therebetween, one end of an arm 49 preferably formed of insulating material. 'I'he arm 49 is secured to the arm 46 by a friction joint means embodying a coupling pin 50 having a nut 5| threaded on one end thereof for compressing a coil spring 52 whereby tension on the friction joint may be suitably adjusted. The spring 52 serves to frictionally clamp the end of the arm 49 between the clamping plates 48. 'I'he outer or free end of the arm 19 is provided with a circular head 53 arranged in the U-shaped free,

end lportion 35 of the spring contact arm 34 whereby movement of the control arm imparts movement to the end portion 35. Therefore, any expansion of the thermostatic tube 40 acts to swing the arms 43 and 49 in a direction for moving the end .portion 35 away from the fixed contact 32 so as to break electrical connection therebetween. This movement of is limited by the adjustable stop 36.

the end portion 35 In operation of the igniting means, and with the circuit breaker C normally closed as in Figure 2, opening of the gas valve 8 permits closing of the contact members 28 and 29 thus closing the control circuit 26 so that a spark is created by the electrode rod Il thus igniting the gas escaping from the jets I0. When the gas is lighted, the thermostat 40 will be heated and expands much faster than does the burner 6. Longitudinal expansion of the thermostatic tube 40 imparts swinging movement to the control arm 43 and moves the contacting end portion 35 away from the stationary contact 32 thus breaking the primary circuit and extinguishing the spark at the lelectrode Il. Continued expansion ofthe therof the thermostatic tube, the free end of the spring contact arm 34 is immediately moved into contact with the. stationary contact 32 and restores the circuit thru the control line 26. Should the valve 8 still be open and the contacts 28 and 29 closed, the spark will again be provided at the electrode for igniting the gas should the gas have been accidentally extinguished or the gas supply momentarily stopped. Should the thermostatic tube 40 be adjusted for a normal starting temperature of say fifty degrees and the temperature drops well vbelow such temperature be,

fore the heater is lighted, in this case, the arms 46 and 49 will adjust themselves automatically to such lowered temperature as shown in Figure 4 so that thermostatic action is immediately effective on lighting the burner. It will therefore be seen that the control period for the circuit breaker is independent of the degree of temperature at which opening and closing of the contact arm 34 takes place. 'I'hat is, opening of the contact arm 34 isv accomplished thru a given rise in temperature 4at the thermostatic control means, and likewise closing of the contact arm is accomplished thru a given drop in temperature at the thermostatic control means. By limiting A Changes in details may be made to the form of invention herein shown and described, without departing from the spirit of the invention or the scope of the following claims.

I claim: 1. In a thermostatically operated switch, a

switch casing, a fixed contact in the casing, a

spring contact arm fixed at one end to the casing and having its free end normally engaging the fixed contact, adjustable stop means for limiting movement of the free end of the contact arm away from the fixed contact, a bell crank" pivoted to the casing providing a long arm and a short arm, a switch arm having one end operatively engaging the free end of the contact ann `long arm, and a thermostatic element connected to said short arm for imparting swinging movement to the bell crank.

2. In a thermostaticaily operated switch, a

fixed contact, a spring contact arm having a U' end portion normally engaging the xed contact, an adjustable stop for limiting movement of the U end portion away -from the xed contact, a control arm embodying self-adjusting arm portions one of which is provided with a circular head engaging in said U end portion for imparting movement to the contact arm, and a thermostatic element for imparting swinging movement to the control arm.

3. In a thermostatically operated switch, a casing, a fixed contact mounted in one end of the casing, a spring contact arm mounted in the casing and having a U end portion yieldably urged into engagement with the fixed contact, an adjustable lstop mounted in the casing for limiting movementof the U portion, a bell crank pivoted in the casing providing a long arm and a short arm, a switch arm pivotally and frictionaily secured at one end; to` said long arm; a circular head at the opposite end of the switch arm engaging said U end portion for imparting movement thereto between the xed contact and said stop, and a thermostatic element pivotally connected at one end to the short arm of the bell crank.

4. In a thermostatically operated switch, a Y

xed contact, a spring contact arm having'a U end 'portion engaging the fixed contact, an adjustable stop for limiting movement of the U end portion away from the fixed contact, a pivoted bell crank providing a long arm and a short arm, said long arm having spaced apart clamping plates at its free end, a switch arm, a coupling pin pivotally connecting the switch'arm at one end between said plates, means for frictionally resisting swinging of the switch arm about its pivot, a circularA head formed at the outer end of the switch arm and engaging in the U end portion, and athermostatic element pivotally connected at one encl to the short arm of the bell crank.

JOSEPH PAGANO. 

